Process for tying bags

ABSTRACT

1,102,776. Sealing bag closures. SHOZO OMORI. 5 May, 1965 [6 May, 1964], No. 18878/65. Heading B8C. A length of wire 1 with a flat 2, Fig. 1, of width equal to its width in a perpendicular direction, is bent to a U-shape with the flat inside the curve of the U and deformed round the mouth of the bag, Fig. 4 (not shown), bulges, Fig. 3, being formed in the ends of the wire during deformation. The wire is secured round the bag mouth between dies 9, 4, Fig. 2, of which the lower, movable die has portions 6 which, when contacted by die 9, are depressed against spring 7.

Se t. 26, 196.7 SHOZO OMORI PROCESS FOR TYING BAGS Filed April 28,- 1965 F/ g. PRIOR ART PRIOR ART YINVENTOR. s H 020 O HOB United States Patent Office 3,343,253 PROCESS FOR TYING BAGS Shozo Omori, 44 Shimo Negishi-cho-Taito-ku, Tokyo, Japan Filed Apr. 28, 1965, Ser. No. 451,573 Claims priority, application Japan, May 6, 1964, 39/ 25.452 3 Claims. (Cl. 29-505) The present invention relates to an improved process for tying bags, and more particularly to a process for tying synthetic resin bags by the employment of novel tying mediums.

A prior art process for tying a synthetic resin bag comprises the steps of placing a U-shaped tying medium formed of circular section wire in to a first die member, inserting the constricted mouth portion of the bag between the legs of the tying medium, bending the legs of the tying medium inwardly toward each other by the first die member, and then compressing the legs from above by a second die member so as to firmly apply the tying medium around the bag mouth. However, since the tying medium has a circular cross section, the bag mouth is contacted and compressed by only the center portion of the curved inner surface of the tying medium. Therefore, if the bag has a large diameter mouth, even when a tying medium is applied around the bag mouth with a strong force, the tying force exerted by the tying medium is subjected to a limitation.

And if a U-shaped tying medium formed of flat metal is used for tying the mouth portion of a synthetic resin bag, the area where the bag mouth contacts with the surface of the tying medium may be larger than in the case acircular cross section tving medium is employed for the same purpose. but when the flat tving medium is compressed from above, the legs of the tying medium tend to bend outwardly resulting inweaker tying strength as compared with the tying strength obtained by the circular cross section tying medium.

Furthermore, when different sizes of circular cross section or fiat type tying mediums are employed, in order to tie the bag satisfactorily a die device which comprises an unper die member and a lower die member has to be modified so that the device may be suitable for particular sizes of the mediums. Even the die device is modi- 4 fied so as to be suitable for particular sizes of tying mediums, uniform and sufficient tying effects cannot be obtained by the employment of such prior art tying mediums because of the above-mentioned disadvantages inherent to them.

- However, when the novel tying medium which will be explained hereinafter is employed for tying bags, the same die device can be employed for various sizes of tying mediums Without the necessity for modifying the device.

Therefore, the present invention is to provide an improved process for tying synthetic resin bags which can tie the bags satisfactorily while eliminating the above disadvantages inherent to the prior art processes referred to hereina-bove.

According to the present invention, a length of wire material having a flat portion and the remaining arcuate portion both of which portions extend in the longitudinal direction thereof is employed for forming a tying medium and the wire material is bent into a U-shape configuration so as to dispose the flat portion inside. Thereafter, the constricted mouth of a synthetic resin bag is inserted between the legs of the tying medium in such a manner that the constricted mouth of the bag is encircled by the tying medium and the fiat portion of the medium is forced to abut against the periphery of the 3,343,253 Patented Sept. 26, 1967 bag mouth with a strong compressive strength whereby the bag is firmly tied by the tying medium.

Another object of the present invention is to eliminate the necessity of modifying the die device even when various sizes of tying media are employed.

The above and other objects, features and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed explanation of the invention in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is a perspective view of wire material useful for forming a tying medium which is to be employed for carrying out the process according to the present invention;

FIG. 2 is a front elevational view of a die device comprising an upper die and a lower die useful for carrying out the novel process and which shows portions thereof in section;

FIG. 3 is a cross-sectional view of the mouth portion of a bag tied according to the novel process;

FIG. 4 is a cross-sectional View taken along the line A-A of FIG. 3 and as seen in the arrow direction therein;

FIG. 5 is similar to FIG. 4, but shows the mouth portion of a bag around which a conventional round section tying medium is tied; and

FIG. 6 is similar to FIG. 3, but shows the mouth portion of a bag around which a conventional flat type tying medium is tied.

Referring now particularly to the accompanying drawings in which like numerals indicate like parts, the numeral 1 designates wire material having a flat portion 2 and the remaining arcuate section portion 3 both of which portions uniformly extend in the longitudinal direction of the wire material, and the material is suitable for forming a tying medium in carrying out the novel process of the present invention. The width of the flat portion 2 is somewhat narrower than the major diameter of the arcuate section portion 3. FIG. 2 shows a die device in which the wire material 1 is bent so as to form a tying medium and a synthetic resin bag is tied by the tying medium. The die device comprises a lower vertically movable die member 4 and an upper stationary die member 9. The lower die member 4 has a U-shaped recess 5 on the upper surface for receiving the wire material 1 and a pair of retractable opposite side pieces 6.

Each of the retractable side pieces 6 comprises upper and lower portions with a spring 7 disposed therebetween so that the upper portion of the respective retractable side piece is normally urged upwardly by the action of its spring 7 and projects above the upper surface of the body of the lower die member 4. Thus, the projected portions of the side pieces 6 form an extension of the recess 5 on the upper surface of the body of the lower die member 4. The numeral 8 designates a tying medium retaining plate which is adapted to abut against both legs of a U-shaped bent tying medium 11 when the same is formed by deforming the wire material 1 in the U- shape recess 5 and hold the tying medium 11 in position While the tying medium 11 is tied around the mouth portion of the bag in the manner of which explanation will be made hereinafter. Any suitable means (not shown) may be employed to move the lower die member 4 toward and away from the upper die member 9. The stationary upper die member 9 has also a reversed U-shape recess 10 on the lower surface which faces the U-shape recess 5 of the lower die member 4.

In carrying out the novel process according to the present invention, the wire material 1 is bent in the recess 5 of the lower die member 4 so as to form a U- shape tying medium with the flat portion 2 disposed in side and thereafter the constricted mouth of a synthetic resin bag 12 is inserted between the legs of the tying medium 11. After the tying medium 11 has been formed and the bag mouth has been inserted between the legs of the tying medium as described hereinabove, the lower die member 4 is moved upwardly toward the upper stationary die member 9 until the tops of the side pieces 6 of the lower die member abut against the lower surface of the upper die member. Thereupon, the side pieces 6 of the lower die member 4 are depressed down by the upper die member 9 and these side pieces are caused to gradually retreat against the action of their springs 7, and accordingly, the upper half portions of the legs of the tying medium 11 are first bent inwardly toward each other by sliding along the inclined side walls of the recess 10 in the upper die member 9 and then compressed by the bottom of the recess 10 whereby the substantially half portions of the legs of the tying medium 11 are deformed so as to form inwardly and outwardly projecting bulges as shown in FIG. 3 which firmly grip the mouth portion of the bag 12 with a strong force. In this case, since the entire area of the inner flat portion 2 of the tying medium 11 sealingly contacts the tied mouth portion of the bag, the mouth portion of the bag is tied covering an area corresponding to the width of the fiat portion 2 of the tying medium, and accordingly, the tying effects by the employement of the novel tying medium 11 are far superior to those obtainable by the employment of the conventional circular section tying medium 15 as shown in FIG. 5. Furthermore, in case flat type material is formed into a U-shape tying medium 16 (see FIG. 6), since the thickness of such a medium is less than the width thereof, when the medium is compressed down, the legs 13 of the strap are forced to bulge outwardly so as to spread apart from each other instead of forming inner bulges as in the employment of the novel tying medium and as a result clearances 14 are formed between the bag and the inside of the bent portions in the legs.

Accordingly, the tying force obtained by the employment of the flat type tying medium is less than that ohtainable by the employment of the circular section tying medium. The present invention can eliminate the above disadvantages inherent to the prior art processes are referred to above. According to the present invention, since the tying medium 11 has a sufficiently thick arcuate section portion in spite of the fact that the flat portion is formed therein, even when the medium is compressed by the die device it is assured that the upper half portions of the legs are bulged inwardly, but not outwardly, whereby the tying medium can apply a strong tying force against the bag.

The contour of the Wire material 1 for the tying medium 11 is not limited to that shown in FIG. 1, but wire materials having various contours may be employed within the scope of the spirit of the present invention as far as such wire materials have flat portions with suitable widths and the remaining portions with thicknesses sufficient enough to assure formation of inwardly projecting bulges when they are compressed.

In order to obtain a satisfactorily tied bag, usually a tying medium to be employed for tying the bag should satisfy the following requirements:

(1) Since the tied mouth portion of a bag tends to open due to an inner pressure which usually ex'sts in the inside of the bag, in order to prevent such tendency from taking place, a tying medium for tying such a bag should have a relatively great modulus of section.

(2) A tying medium should have such a c oss-section configuration that the tying medium may contact a bag at a relatively large area and distribute its tying force uniformly over the whole contact area of the bag.

The novel tying medium to be employed in carrying out the process of the present invention is advantageous in the fact that the same possesses both a great modulus of section which a round section tying medium has and a wide contact surface which a fiat type tying medium has.

It will be understood that modifications and variations on the embodiment of the invention as disclosed herein may be resorted to without departing from the scope of the concept of the present invention. Therefore, the scope of the invention should be limited only by the scope and proper interpretation of the claims appended hereto.

What is claimed is:

1. A process for tying a bag comprising the steps of bending a length of circular cross-section wire material having a fiat portion extending in the longitudinal direction of said wire and a thickness substantially equal to the width of said flat portion so as to form a U-shaped tying medium with the flat portion facing inside, inserting the constricted mouth of a bag between the legs of said U-shaped tying medium and against said flat portion thereof, and compressing said tying medium so as to firmly apply the upper half portions of said legs around the bag mouth and into end abutting relationship whereby inwardly extending bulges may be formed on said portions of the legs and the flat portion thereof is in gripping relationship with said constricted mouth of the bag.

2. A process as set forth in claim 1, in which said bag is formed of synthetic resin or the like.

3. A process as set forth in claim 1, in which both said bending step of the wire material into a U-shape and said bulge forming step are carried out in the same die device comprising an upper stationary die member and a lower vertically movable die member, but said steps are carried out in succession with the bending step first.

References Cited UNITED STATES PATENTS 308,087 11/1884 McDonald 29-243.56 2,716,751 9/1955 Kelem 29-243.57 2,759,256 8/1956 Bergan 29-515 2,879,512 3/1959 Tipper 29-24357 X 2,886,816 5/1959 Hill 29243.57 X 3,031,671 5/1962 Wilson et al. 29-505 3,293 355 12/1966 Gropp et a1. 29-517 X CHARLIE T. MOON, Primary Examiner. 

1. A PROCESS FOR TYING A BAG COMPRISING THE STEPS OF BENDING A LENGTH OF CIRCULAR CROSS-SECTION WIRE MATERIAL HAVING A FLAT PORTION EXTENDING IN THE LONGITUDINAL DIRECTION OF SAID WIRE AND A THICKNESS SUBSTANTIALLY EQUAL TO THE WIDTH OF SAID FLAT PORTION SO AS TO FORM A U-SHAPED TYING MEDIUM WITH THE FLAT PORTION FACING INSIDE, INSERTING THE CONSTRICTED MOUTH OF A BAG BETWEEN THE LEGS OF SAID U-SHAPED TYING MEDIUM AND AGAINST SAID FLAT PORTION THEREOF, AND COMPRESSING SAID TYING MEDIUM SO AS TO FIRMLY APPLY THE UPPER HALF PORTIONS OF SAID LEGS AROUND THE BAG MOUTH AND INTO END ABUTTING RELATIONSHIP WHEREBY INWARDLY EXTENDING BULGES MAY BE FORMED ON SAID PORTIONS OF THE LEGS AND THE FLAT PORTION THEREOF IS IN GRIPPING RELATIONSHIP WITH SAID CONSTRICTED MOUTH OF THE BAG. 